Despite the dire posts here and thanks to a techie friend's encouragement, I decided to go ahead with the installation, using the Combo 10.7.4 and Safari 5.1.7 updates that I downloaded last night.
Before installing, I ran TimeMachine and updated my external hard drive that is a clone of my 2011 MacBookPro so that I could revert if 10.7.4 broke for me as it has for those who posted recently.
Next I attached my updated, cloned hard drive to my MBP. I located the Combo 10.7.4 Update on my MBP and installed that onto the clone. Not only did this method guarantee that my MBP would continue to function in 10.7.3, but I could continue to be online while waiting for the installation to complete.
Next I installed the Safari 5.1.7 update on the clone.
After both installations were complete, I rebooted from the updated clone, now running 10.7.4, with no hardware or software problems. Network, printer all good. Safari 5.1.7 worked fine too.
While still booted from the clone, I installed the combo 10.7.4 update first and the Safari 5.1.7 next onto my MBP.
Next I shut down, removed the cloned drive, and rebooted from my MBP from which I am now writing. The install seemed to take longer on the MBP than on the cloned drive but otherwise all is good with both my MBP and its clone.
Suggestion for Apple:
Please add the Combo OS X update as a choice — along with the Delta update — via Software Update. Doing so would allow users with hi-speed Internet access to have a better update experience using the Combo update.
Folks who are still tethered to dial-up Internet access can either wait longer for the Combo download or do the Delta if they are impatient.
Doing so could reduce the number of problem installations and complaints to Apple.